This invention relates to mechanical disc brakes and, particularly, to disc brakes of the floating caliper type including a force converting mechanism for converting a rotary input force into a linear output force which is directly applied to one of the friction pads, and a caliper slidably mounted on a stationary member for transmitting the reaction of the output force to the other friction pad.
Various disc brakes of the type aforementioned are known to the public and, one of co-inventors of the present invention has also proposed similar disc brakes in Japanese Patent Application Nos. 17796/1976 and 17797/1976 (which are now disclosed to the public under Japanese Patent Disclosure Nos. 101368/1977 and 101369/1977 respectively).
Usually, the force converting mechanism includes a rotatable member rotatably mounted on a housing of the disc brake and adapted to receive the input force in the form of torque, a ramp member mounted in the housing for moving relatively toward and away from to the rotatable member, co-acting surfaces formed on the rotatable member and the ramp member and being inclined with respect to the direction of relative movement between both members, and at least one force transmitting member interposed between the inclined surfaces for transmitting force therebetween to reduce frictional resistance caused therefrom.
Conventionally, a dust preventing boot has been provided with the opposite ends thereof secured to the housing and the rotatable member to prevent ingress of dust or water into the force converting mechanism, and the boot mounting operation has been effected after the force converting mechanism has been installed in the housing. However, the space between the housing and the rotatable member is usually narrow and the boot has been secured to a specified small area portion of the housing. Thus, the boot mounting operation has been troublesome and time consuming. Further, it has been necessary to use additional parts such as a retaining spring or the like to secure the boot to the housing, thus complicating the configuration of the boot, increasing manufacturing costs and increasing the difficulty of the mounting operation.